Sally Hansen is a good brand.
The Color depends on your personality and your skin tone.
If you have a lighter skin tone light colors will be nice (Baby pink, beige, clear)
If you have a darker skin tone bright popping colors are nice, Think rainbow. (And also bright pink)
Stay away from black and dark brown. You will look dull.

Not necessarily; I've worn black loads of times and it actually sets off your nails sometimes. Give black nails a white or glitter tip to jazz them up. There are loads of effects you can do yourself on nails; like nail jewels and transfers, or putting a tip. Just get a sticker and put on the nail to get a straight line to paint.

Try a dark blue, pink, purple or red instead of black then. The dark colour with the white tip works well on anyone. You'll need practice to get it just right tho; or, if you don't dare to do a white tip, just paint a glitter tip instead. ^^

How about say, painting one hand's nails pink and the other blue? Or go for a rainbow effect by painting your nails red, yellow, green, blue and purple?

Yup. ^^ Make the colours contrasting tho, like pink/blue; red/green; black/white. And if you've got a steady hand, you could even try painting each nail a different colour on each side. And definitely go for nail transfers; you can buy them in places like Claire's.

Black is actually one of the most worn colors by teenage girls around the world. I recommened baby blue or lime green. They look very different from all those people who wear light pink. But mainly, if you would want to buy nail polish, it would depend on your personality, and style.

Oooh, the only thing I like about all the fake populars of my school are their nails. They are very stylish with them, and I do copy them...on rare occassions.

Something that is very cute is:

Paint your nails with a clear coat to make them shine. Then add black tips to them, or white tips, and then use the opposite colour (white with black, black with white) to distinguish the tip from the nail. That means putting a thin stripe of the opposite colour on the between the tip and the nail. It's very cute.